1. Pressure cook the soaked chole along with salt and little turmeric powder for 5-6 whistles. Keep it aside for the pressure to release.
2. Heat a wide thick-bottomed pan and add oil. Crackle the mustard seeds.
3. Throw in the chopped onions and saute till raw smell is gone. Add the crushed ginger, garlic and chillies. Saute till oil starts leaving the mixture.
4. Add the chopped tomatoes and saute till oil leaves.
5. Now add the powders (chilly powder, garam masala, salt, coriander powder) and saute well for atleast 30s.
6. Add the cooked chole to the masala along with the water in the cooker. Let it boil in the masala for 5-6 minutes, until the gravy thickens.
7. Sprinkle the amchoor powder if the curry isn't tangy enough. Check for salt and add if needed.
8. Garnish with chopped coriander leaves and serve hot with chapathis.